This Golang SDK is thin wrapper of MegaFuel clients, offering a streamlined interface to interact with the MegaFuel.
- Install dependency
$ go get -u github.com/nodereal/megafuel-go-sdk- Example
package main
import (
"context"
"crypto/ecdsa"
"fmt"
"log"
"math/big"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/hexutil"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/ethclient"
"github.com/gofrs/uuid"
"github.com/node-real/megafuel-go-sdk/pkg/paymasterclient"
"github.com/node-real/megafuel-go-sdk/pkg/sponsorclient"
)
const PAYMASTER_URL = "https://bsc-megafuel-testnet.nodereal.io"
const CHAIN_URL = "https://data-seed-prebsc-2-s1.binance.org:8545/"
const SPONSOR_URL = "https://open-platform.nodereal.io/<api-key>/megafuel-testnet"
const POLICY_UUID = "a2381160-xxxx-xxxx-xxxxceca86556834"
const RECIPIENT_ADDRESS = "0x8e9......3EA2"
const YOUR_PRIVATE_KEY = "69......929"
func main() {
sponsorClient, err := sponsorclient.New(context.Background(), SPONSOR_URL)
if err != nil {
panic(err)
}
policyUUID, _ := uuid.FromString(POLICY_UUID)
success, err := sponsorClient.AddToWhitelist(context.Background(), sponsorclient.WhiteListArgs{
PolicyUUID: policyUUID,
WhitelistType: sponsorclient.ToAccountWhitelist,
Values: []string{RECIPIENT_ADDRESS},
})
if err != nil || !success {
panic("failed to add token contract whitelist")
}
// Connect to an Ethereum node (for transaction assembly)
client, err := ethclient.Dial(CHAIN_URL)
if err != nil {
log.Fatalf("Failed to connect to the Ethereum network: %v", err)
}
// Create a PaymasterClient (for transaction sending)
paymasterClient, err := paymasterclient.New(context.Background(), PAYMASTER_URL)
if err != nil {
log.Fatalf("Failed to create PaymasterClient: %v", err)
}
// Load your private key
privateKey, err := crypto.HexToECDSA(YOUR_PRIVATE_KEY)
if err != nil {
log.Fatalf("Failed to load private key: %v", err)
}
publicKey := privateKey.Public()
publicKeyECDSA, ok := publicKey.(*ecdsa.PublicKey)
if !ok {
log.Fatal("Error casting public key to ECDSA")
}
fromAddress := crypto.PubkeyToAddress(*publicKeyECDSA)
// Get the latest nonce for the from address
nonce, err := client.PendingNonceAt(context.Background(), fromAddress)
if err != nil {
log.Fatalf("Failed to get nonce: %v", err)
}
toAddress := common.HexToAddress(RECIPIENT_ADDRESS)
tx := types.NewTx(&types.LegacyTx{
Nonce: nonce,
GasPrice: big.NewInt(0),
Gas: 21000,
To: &toAddress,
Value: big.NewInt(1e18),
})
// Convert to Transaction struct for IsSponsorable check
gasLimit := tx.Gas()
sponsorableTx := paymasterclient.TransactionArgs{
To: &toAddress,
From: fromAddress,
Value: (*hexutil.Big)(big.NewInt(1e18)),
Gas: (*hexutil.Uint64)(&gasLimit),
}
// Check if the transaction is sponsorable
sponsorableInfo, err := paymasterClient.IsSponsorable(context.Background(), sponsorableTx)
if err != nil {
log.Fatalf("Error checking sponsorable status: %v", err)
}
fmt.Printf("Sponsorable Information:\n%+v\n", sponsorableInfo)
if sponsorableInfo.Sponsorable {
// Get the chain ID
chainID, err := client.ChainID(context.Background())
if err != nil {
log.Fatalf("Failed to get chain ID: %v", err)
}
// Sign the transaction
signedTx, err := types.SignTx(tx, types.NewEIP155Signer(chainID), privateKey)
if err != nil {
log.Fatalf("Failed to sign transaction: %v", err)
}
txInput, err := signedTx.MarshalBinary()
if err != nil {
log.Fatalf("Failed to marshal transaction: %v", err)
}
// Send the transaction using PaymasterClient
_, err = paymasterClient.SendRawTransaction(context.Background(), txInput)
if err != nil {
log.Fatalf("Failed to send sponsorable transaction: %v", err)
}
fmt.Printf("Sponsorable transaction sent: %s\n", signedTx.Hash())
} else {
fmt.Println("Transaction is not sponsorable. You may need to send it as a regular transaction.")
}
}More examples can be found in the examples.